Tubing plug



United Staes f f TUBING PLUG Raoul J. Bethancourt, Dallas, Tex., lassignor to Sun Oil This invention relates to devices for catching falling objects in well bore tubing and more specifically to such v,

devices designed to permit the passage of iiowing bore-` hole uids and preserve the strata beneath the end of the tubing for further production operations.

Various types of closure devices such as suspended baskets, bearing plugs, casing plugs and the like have been used in well bore's and well bore casings for -a variety of reasons. 'I'he means for suspending these devices take several forms which can be divided roughly into two general classes, a self-,contained gripping means, and means made of resilient material flexible enoughto wedge in the aperture. In some instances, depending on the purpose to be served, the device is peripherally uted to permit passage of fluid around it.

In the development of oil fields, where the bearing strata is tapped successively as the borehole is drilled deeper, special problems are encountered, particularly with respect to tubing used in the process, as distinguished from casing or the rough borehole itself. As the tubing approaches each successively deeper strata, borehole operations such 4as using agun perforator, 'or exploratory instruments, must be used below the.y open end of the tube. It is necessary to keep the working space below the tube end free of foreign matter, such as dropped tools, fittings, bolts, screws, etc., generally termed junk by well drillers. It is, therefore, a primary object of this `invention to provide a tubing stop to prevent dropped materials from fouling the later-t-o-be-developed area of the borehole.

In addition to protecting the sub-strata for future operations, continued use of the tubing closure means or plug, as it is called, presents different requirements. It is necessary that the iiuid of the well bore hole pass freely around the plug. A maximum of opening must be left in the tubing yet prevent junk below the plug. It is a further object of this invention to provide a tubing plug of a cross-section reducing the obstruction t-o passing uid ilow to a minimum.

- It will be evident that the lluted periphery of known casing and borehole closures mentioned above will not afford this minimum obstructionl requirement. An additional reason for larger clearances through and around the tubing plug is the presence of sand-and other earth residues in the ilowing iiuid. The presence of these suspended solids detrimentally affects the closure members of the second general class, namely, those containing gripping means. To both place and remove these closures, it is required that the gripping mechanism be free of grit and silt deposits. Once fouled, the work to remove these devices is endless. An additional object of this invention is to provide a tubing plug which remains free of xed engagement with the tubing and maybe readily removed and replaced.

Other and further objects of the invention will become Vapparent as the description proceeds, reference being ,listened oct. 21, 195s 2 made to the accompanying drawings forming a part of the disclosure, wherein "Figure 1 is an elevational view,-in section, of the tubing plug in place; and

Figure 2 is a sectional view of Figure l taken on lines 2 2 of that figure.

Referring to Figure l, wherein, for purposes of illustration, aprefered embodiment of the invention is illustrated, the numeral 10 is used to designate an upper rsection of tubing as it appears in place in a well borehole. A collar 1.2 of the internally threaded type normally connects theupper section of tub-ing 10 with a lower section 11 inV threaded engagement. `A lock seat 14, shown here as a simple ringor liange member, is engaged, in this 'cas e ,between the collar 12 and an adapter member 16 which in turn threadedly engages both the 'collar 14 and the lower piece of tubing 11.

. The tubing plug of this invention, inclusively numbered 13, is shown in tubing sections 10 and 11 in engagef ment with the lock seat 'ring or flange 14 Iat the shoulder portion 18. Generally, the plugmember may be described as having a lower linned portion adapted to pass through the llange orv seat ring 14 until* a widened or shouldered part rests-thereon. The upper portion, atr tached to the lowerfnned portion, is a tubular connector with a top llange ring for engagement with vconventional from dropping p fishing tools.: Specifically the sectional view of Figure 2 indicates the adopted form of this application showing engaging shoulders 18 as part of .a 'cross' of equal arms for the finnedportion. Such a device will berecognized as easily manufactured from angle irons of proper size, being welded at the angle junction. The tins or legs 20 extend downwardly from the shoulder portion 18 a sufficient distance to stabilize the upper portion of the device 'as the borehole liquids flow upwardly past it. The upper portion of the intersecting orl crossedr legs 20 are welded to a tubular fishing neck 22 which is hollow as indicated by the dotted lines and topped by the oonventional flange shaped portion 24 for engagement with well-known wire line iishing units. v

By such construction, the crossed legs 20 being tapered at 2,6 to engage the annular portion of the fishing neck 22, all obstruction to upwardly liowing liquids is reduced to 1a minmum. The space between the crossed legs 20 is freely open to pass such liquid and the liquids in turn may ow aroundand through the fishing neck. At the same time theslope of the shoulder 28 at the top of the legs 20 will divert and hold dropped tools or other objects and prevent them from cluttering the strata below the bottom` of the tube, interfering with later operations. A

From the above description the use and objects of this device will be readily understood. It is easily lowered into position by Ia wire line device or it may be droppedr into the tubing and nd its own seat on the pre-positioned flange or lock s-eat ring in a fashion similar to the use of go-devils. By :selecting the `collar section in which to insert theseal ring, the working elevation of the tube plug is established. The plug may be removed preliminarily to exploration below the tube, or for the insertion of a gun perforator intended to open lower petroleumbearing strata, by the use of the `wire-line tool with a fishing element or it may be'pumped out by exercising excessive pressure in the pumped liquids ofthe borehole.`

Under normal pressure conditions, the rplug'will remaink in contact with the seal ring as it presents' little surface will prevent jun from falling to the later operating area below the tubing, :and will also hold. such. junk for removal by conventional fishing methods, withinthe f bounds of the tube. Should it be impossible or iuriprac`fv ticable to extract thedropped objects by ishing or fluid force, removal of the tubing will bring all such objects out of the hole as they are supported by the plug in the tube.

A plug especially designed for tubing used in 'succes sive strata drilling having special features is disclosed. lt will support dropped objects within the tubing, keeping lower strata operable for later devel-dpment, and still permit maximum ow of iiuids upwardly through the tubing.

What is claimed is:

1. A device for plugging well tubing to catch dropped objects comprising, in combination with the tubing, ange means reducing the diameter of the` well tubing inserted at a selected eievation therein, and a plug adapted to slide through the tubing having a lower section of intersecting vanes concentrically connected and fastened to ya'hollow'fishing neck at the top thereof, the vanes reduced in diameter for substantially the lower half of the plug to slide through and engage the ange means with the full tube diameter larger upper half in obstructing relation yet permitting the passage of well liquids freely through the ange and the apertures between the vanes and the hollow iishing neck.

2. ln combination with tubing adapted to be placed in; a well bore a lock seat ring connected into the tubing at a `predetermined elevation having a central aperture of less diameter than the tubing forming a supporting surface in the tubing, and a plug of radially extending vanes longitudinally intersecting in concentric alignment with the tubing, said vanes reduced in diameter below plug through and to operably rest on the lock seat ring,

' and fishing tool connecting means in operating engagethe middle of the plug to pass the lower portion of the ment with the top of said vanes substantially above the lock seat ring aiording free passage of well fluids around the plug.

3. A device for obstructing tubing to prevent downward passage of solid 4objects below a selected elevation yet permitting free passage Iof well fluids, comprising, in combination with a lock seat ring adapted to reduce the diameter of the tubing, a plug having a body portion of radially extending vanes longitudinally yintersecting concentrically of the plug, the port-ion of the vane body extending below the middle of the plug being of a diameter to pass through the lock seat ring, the upper diameter approximating the tubing diameter cau-sing the plug to engage and rest on the ring, and a iishing neck for cooperation with a fishing tool to remove the plug from the lock seat ring, said neck connected to the top of the radially extending vanes substantially above the lock seat' ring permitting free uid passage through the ring and around the plug.

References Cited in the tile of this patent UNITED STATES PATENTS 1 Anza-1,15( 

1. A DEVICE FOR PLUGGING WELL TUBING TO CATCH DROPPED OBJECTS COMPRISING, IN COMBINATION WITH THE TUBING, FLANGE MEANS REDUCING THE DIAMETER OF THE WELL TUBING INSERTED AT A SELECTED ELEVATION THEREIN, AND A PLUG ADAPTED TO SLIDE THROUGH THE TUBING HAVING A LOWER SECTION OF INTERSECTING VANES CONCENTRICALLY CONNECTED AND FASTENED TO A HOLLOW FISHING NECK AT THE TOP THEREOF, THE VANES REDUCED IN DIAMETER FOR SUBSTANTIALLY THE LOWER HALF OF THE PLUG TO SLIDE THROUGH AND ENGAGE THE FLANGE MEANS WITH THE FULL TUBE DIAMETER LARGER UPPER HALF IN OBSTRUCTING RELATION YET PERMITTING THE PASSAGE OF WELL LIQUIDS FREELY THROUGH THE FLANGE AND THE APERTURES BETWEEN THE VANES AND THE HOLLOW FISHING NECK. 